---

Section 2.4

---

Vocabulary

---

(none)

---

Outline

---

• Devices that Monitor Faults
  • 4 devices to monitor faults
  • Tiltmeters,laser-ranging devices,Creep meters, Satellite monitors
  • earthquakes almost always strike without warning
  • only clue may be the slight rise and fall of the land
• *Creep Meters*
  • measures horizontal movement in the floor
  • measure the amount of movement the fault has made
• *Laser-ranging Device*
  • uses a laser beam to find any movement (even if it is very tiny)
• *Tiltmeters*
  • like a carpenter's level
  • measure amount of tilt along the fault
• *Satellite Monitors*
  • make image of faults
  • the waves echo back into space,and the satellite records them
• Monitoring Risk in the United States
  • geologists can NEVER predict EXACTLY when and where the quake will strike
  • earthquake risk is highest along the Pacific Coast of US ( California, Washington, Alaska)
  • severe earthquakes are seldom east of the Rockies

Southern Texas and Southern Florida have NO earthquakes-------
*Creep Meter*

*Laser-Ranging Device*

*Tiltmeter*